The embodiments herein relate generally to subterranean formation operations and, more particularly, to crush-resistant proppant particulates.
Subterranean wells (e.g., hydrocarbon producing wells, water producing wells, and the like) are often stimulated by hydraulic fracturing treatments. In hydraulic fracturing treatments, a gelled treatment fluid is often pumped into a portion of a subterranean formation at a rate and pressure such that the subterranean formation breaks down and one or more fractures are formed therein. Particulate solids, such as graded sand, are typically suspended in at least a portion of the treatment fluid and deposited into the fractures in the subterranean formation. These particulate solids, or “proppant particulates” (also referred to simply as “proppants”) serve to prop the fracture open (e.g., keep the fracture from fully closing) after the hydraulic pressure is removed. By keeping the fracture from fully closing, the particulates aid in forming conductive paths through which produced fluids, such as hydrocarbons, may flow.
Hydraulic fracturing treatments may also be combined with sand control treatments, such as a gravel packing treatment. Such treatments may be referred to as “frac-packing” treatments. In a typical frac-packing treatment, a gelled treatment fluid comprising a plurality of particulates is pumped through an annulus between a wellbore tubular mounted with a screen and a wellbore in a subterranean formation. The fluid is pumped into perforations through a casing, or directly into the wellbore in the case of open hole completions at a rate and pressure sufficient to create or enhance at least one fracture, and the proppant particulates are deposited in the fracture and in the annulus between the screen and the wellbore. The proppant particulates aid in propping open the fracture, as well as controlling the migration of formation fines or other loose particles in the formation from being produced with produced fluids.
The proppant particulates placed in a fracture or in the annulus during a frac-packing operation may form a “proppant pack” or “gravel pack” (collectively referred to herein as “proppant pack”). As used herein, the term “proppant pack” refers to a collection of proppant particulates, such as in a fracture in a subterranean formation. The degree of success of a fracturing operation (both a traditional hydraulic fracturing operation and a frac-packing operation) depends, at least in part, upon fracture porosity and conductivity once the fracturing operation is complete and production is begun. The interstitial spaces between individual proppant particulates in a proppant pack permit production fluids to flow therethrough and to be recovered at the surface.
Commonly used proppant particulates generally comprise substantially spherical particles, such as graded sand, bauxite, ceramics, or even nut hulls. When forming a proppant pack, the proppant particulates may become crushed or otherwise compacted within fractures upon removal of hydraulic pressure, thereby potentially forming non-permeable or low permeability masses within the fracture rather than desirable high permeability masses. Such low permeability masses may choke the flow path of the fluids within the formation. Furthermore, the proppant particulates may become embedded in particularly soft formations, negatively impacting production. Because the fracture porosity is closely related to the strength of the placed proppant particulates and the size and shape of the placed proppant, the presence of crushed or a mixture of crushed and non-crushed proppant particulates in a fracture may greatly reduce the permeability of the fracture and thus hydrocarbon production.